Green Comet Lovejoy Keeps Wowing Amateur Astronomers...

Amateur astronomers and astrophotographers around the globe have been keeping their eyes on the distinctly green glow of Comet Lovejoy, a cosmic object discovered last year that continues to amaze in telescope views. New images (and a short movie) of Comet Lovejoy as it makes a close pass by the Earth.

On Jan. 10, amateur astronomer Steve Siedentop took a series of 100 images of Comet C/2014 Q2, also known as Comet Lovejoy, as it passed over Grayson, Georgia. Siedentop then compiled the images into an aweseom time-lapse video of Comet Lovejoy showing the icy wanderer move across the night sky.

While Lovejoy appears to be moving rather quickly in the video, the images were taken over a 2-hour time span, between 11 p.m. EST (0400 GMT) and 1 a.m. EST (0600 GMT). To capture the images, Siedentop used a Meade Series 5000 80mm triplet APO and a Canon T2i camera using BackyardEOS

Siedentop isn't the only stargazer to cast his gaze up at Comet Lovejoy. The UK-based astronomer Nick Howes snapped an incredible shot of the Comet Lovejoy streaking across the sky. The image shows the comet wrapped in a brilliant green cloud of gas, with a wispy blue and purple tail trailing behind. Howes told Space.com that he took the image using the remotely operated Siding Spring Observatory in Australia and obtained via the Tzec Maun Network.

Comet Lovejoy is still visible in binoculars or small telescopes for observers with clear, dark skies.   

The newfound comet, officially known as Comet Lovejoy C/2014 Q2, was first spotted by Australian amateur astronomer Terry Lovejoy last August. Comets are automatically named after the person who discovers them, and this is Lovejoy's fifth comet discovery to date (hence, there are references to another Comet Lovejoy prior to August 2014).  

The radiant green light from Comet Lovejoy takes center stage in another recent image, this one captured veteran astrophotographer Justin Ng based in Singapore. Ng took the photograph on the night of Jan. 11 over a period of about 40 minutes.

Comet Lovejoy's green color is likely due to the presence of two gases — cyanogen (CN)2 and diatomic carbon (C2) — according to Tanya Hill of the Museum Victoria in Australia.

"The gases glow green when their molecules are ionized or excited," Hill wrote in an article for The Conversation. "Ionization causes electrons within the molecules to gain energy and when the electrons drop back down to their normal state, they give off light of a certain wavelength. For these molecules they emit green light, and since they are very strong emitters, their green color dominates the comet."

The green color makes Comet Lovejoy look like a glowing green emerald in a pile of white diamonds in this image taken by Victor Rogus in Jadwin, Missouri. The comet is in the lower half of the image, near the center. To the right of the comet, a meteor streaks across the sky.

Supernova Blast in Superwind Galaxy Glows in Amateur Photo..

This stunning image shows a bright supernova in the Superwind galaxy taken on Jan. 2 by a night sky photographer in Singapore. 

The supernova, called ASASSN-14lp, was discovered in early December and photographed here by veteran astrophotographer Justin Ng.

"This Type la supernova is located in the spiral galaxy, Superwind galaxy, in Virgo that is approximately 80 million light-years away from Earth," Ng wrote in an email to Space.com, adding the image is the result of a 2-hour exposure. Type Ia supernovas are generally thought to originate from white dwarf stars in a close binary system.

According to Ng, supernova ASASSN-14lp has been getting brighter since it's discovery and became the second brightest supernova of the year 2014 with an 11th magnitude on the reverse scale used by astronomers to measure the brightness of objects in space. On this scale, smaller numbers represent brighter objects. The dimmest objects visible to the human eye are about magnitude 6.5. [Supernova Photos: How Stars Die]

The Superwind galaxy NGC 4666 is a starburst galaxy where intense star formation is taking place. A combination of strong winds from massive stars and supernova explosions create a continuous flow of gas from the galaxy.

Saturn and the Moon Share Predawn Close Encounter on Friday

Early Friday morning, if skies are clear, you have a good chance to catch sight of a lovely waning crescent moon pairing off with the ringed wonder of the solar system: the planet Saturn.  

Start looking low toward the east-southeast horizon around 3:30 a.m. your local time Friday (Jan. 16). Soon after the crescent moon — 21 percent illuminated — emerges from beyond the horizon, you’ll notice a bright non-twinkling yellow-white "star" shining sedately almost directly below it.

That will be Saturn.

If you have any obstructions, such as buildings or trees in your southeastern viewing area, you may have to wait awhile as Saturn and the moon slowly climb higher in the sky. They will be at their highest, appearing roughly one-quarter of the way from the horizon to the point directly overhead (the zenith) at around 5:40 a.m. local time – the start of astronomical twilight. [Related: The Brightest Planets in January's Night Sky]

By the break of dawn, Saturn will appear about 1.1-degrees below and a bit to the right of the moon. The apparent width of the moon is roughly equal to one-half of a degree, so Saturn will appear just over two moon widths from the moon itself.

In order to see the famous rings of Saturn however, you'll need a telescopemagnifying at least 30-power. Their north face is now tilted more than 24.7 degrees to our line of sight. The rings have not been so inclined since late June 2004.

Saturn is currently 977 million miles (1.56 billion kilometers) from Earth. On the other hand, the moon is more than 4,100 times closer to Earth, at a distance of 235,300 miles (378,700 km).

There is another striking target in the Friday predawn sky for the eagle-eye observer. The 1st-magnitude reddish star Antares will be shining 10 degrees (the equivalent of the width of your clenched fist held out at arm's length) to Saturn's lower left. Saturn appears to glow about 0.4 magnitude brighter than Antares. 

Currently Saturn lies within the head of Scorpius, the Scorpion, which resembles a "fence" of 2nd and 3rd magnitude stars. Saturn is still about four months from opposition and as such will continue to slowly grow in prominence in the days and weeks to come.

Epic Landing on Saturn's Moon Titan Remembered 10 Years Later...?

Ten years ago today (Jan. 14), humanity got its first up-close look at a bizarre, frigid moon that may be capable of supporting life as we know it.

The European Space Agency's (ESA) Huygens probe touched down on the surface of Saturn's huge moon Titan on Jan. 14, 2005, three weeks after being deployed from its mothership, NASA's Cassini spacecraft. For the first time ever, an emissary from Earth had landed softly on a world in the outer solar system.

"I distinctly recall the dreamy feeling of being in one universe one moment and in another universe the next," Cassini imaging team leader Carolyn Porco wrote of Huygens' landing in a blog post today. "But it was no dream. We had, without doubt, journeyed to Titan, 10 times farther from the sun than the Earth, and touched it. The solar system suddenly seemed a very much smaller place."

Cassini reached the Saturn system in July 2004 and thus had already observed Titan by the time Huygens touched down. But the lander beamed home information impossible to obtain from afar, a data haul that began during Huygens' two-and-a-half-hour descent through the moon's thick atmosphere.

"The images taken by the falling probe and released to the public that night were everything our images from orbit were not: unfiltered, exquisitely detailed views of the moon's surface and unambiguous in their account," Porco wrote.

Those images revealed what appeared to be a shoreline, as well as snaking channels that had obviously been carved by flowing liquid, she added. But that liquid was not water; Titan has a hydrocarbon-based weather system

"It was circumstantial but incontrovertible evidence for the liquid hydrocarbons that we had strained from orbit to find, and thrilling beyond measure," Porco wrote. "It was soon to be followed, after landing, by another unforgettable sight, under a cloudy sky and across a cobble-strewn ground to the moon's horizon in the distance."

Huygens kept sending data to Earth from Titan's freezing surface for 72 minutes before its batteries died and the probe went dark.

The lander's measurements and observations helped lift the veil of mystery that had enshrouded Titan. For example, Huygens took a detailed profile of Titan's nitrogen-dominated atmosphere, gathering temperature, pressure and density readings over a wide range of altitudes.

Furthermore, Huygens' analyses of Titan's atmospheric methane did not support the suggestion that the gas was produced by microbes, ESA officials said. (Most of the methane found in Earth's atmosphere has a biological origin.)

You can read more about Huygens' discoveries here, in a top 10 list ESA compiled to commemorate today's anniversary.

While Huygens ceased operations shortly after touching down on Titan, Cassini has continued to study the huge moon (along with Saturn itself, and many of its other moons). For example, over the course of more than 100 flybys, Cassini has mapped much of Titan's surface and, using radar, probed the depth of some of the moon's biggest hydrocarbon seas. Moreover, gravity measurements by Cassini suggest that Titan harbors a subsurface ocean of liquid water, NASA officials said.

The $3.2 billion Cassini-Huygens mission — a joint effort of NASA, ESA and the Italian Space Agency — launched in 1997. The Cassini spacecraft is scheduled to keep making observations through September 2017, when the orbiter will end its life with an intentional death dive into the ringed planet's thick atmosphere.

Has Europe's Long-Lost Beagle 2 Mars Lander Been Found?

The U.K. Space Agency is holding a news conference Friday (Jan. 16) about Europe's Beagle 2 Mars lander, prompting speculation that the probe has finally been found more than 11 years after dropping off scientists' radar during its journey to the Red Planet.

The U.K.-led Beagle 2 was supposed to touch down on Dec. 25, 2003. The lander successfully deployed from the European Space Agency's (ESA)Mars Express orbiter on Dec. 19 of that year, but no touchdown confirmation came, and most experts think Beagle 2 crashed on the Red Planet's surface.

The lineup at Friday's three-hour press event, which will be held in London, suggests that the long search for the lander or its remains may be over. The speakers include Beagle 2 Manager Mark Sims; U.K. Space Agency Chief Executive David Parker; Alvaro Giménez Cañete, ESA's director of science and robotic exploration; and John Bridges, a science team member on NASA's Curiosity rover and Mars Reconnaissance Orbiter (MRO) missions.

Bridges works with MRO's HiRISE (High Resolution Imaging Science Experiment) camera, which takes supersharp pictures of the Martian surface. HiRISE has photographed the Curiosity and Opportunity rovers from space, and it also found NASA's twin Viking landers, which touched down on the Red Planet in 1976.

The news conference will take place from 9:15 a.m. until 12:15 p.m. local time Friday at the Royal Society's Kohn Centre in London. It is unclear at the moment if the event will be webcast.

Beagle 2 was part of the Mars Express mission, which launched in June 2003. The Mars Express orbiter, which served as Beagle 2's mothership, is still studying the Red Planet, more than 11 years after its arrival.

The 3.3-foot-wide (1 meter) lander resembled a large pocket watch, whose outer casing was supposed to open upon the craft's landing on Mars. The solar-powered Beagle 2 was designed to study Red Planet geology, weather and climate, as well as search for possible signs of Martian life.

The total cost of the Mars Express mission is 300 million euros (about US $350 million at current exchange rates), ESA officials say.

Scientists Observe Solar System Planets Like Alien Worlds

"It takes one to know one," as the old truism goes. When it comes to unraveling the mysteries of far-off exoplanets, the same holds true — one more reason why astronomers want to thoroughly understand the local planets right here in our Solar System.

A new scientific paper moves the ball forward in this regard by simulating how several rocky Solar System bodies would look ifglimpsed at the light-years distanceof alien worlds. Across such great spans, exoplanets are just dim specks. But what little light does get to us could, the study suggests, imply intriguing details about their surface features, provided we know what to look for.

Previous studies of Earth have demonstrated that oceans, continents and ice caps bounce back strikingly different amounts of light into space. Models demonstrate that even from considerable distances, an observer would be able to pick out the different types of surface materials of water, land and ice.

The new study extends this concept to solid worlds unlike Earth, such as Mars and the Galilean moons, to broaden our basis for comparison.

"We eventually want to investigate the surface environments of Earth-like exoplanets, and for this purpose the observable signatures of Earth have been widely studied," said lead author Yuka Fujii, a postdoctoral research scientist at the Tokyo Institute of Technology's Earth-Life Science Institute. "To interpret the data of unknown planets obtained in the future, we also need to know the possible variety of observable features of other, non-Earth-like planets."

The study, titled "Geology and Photometric Variation of Solar System Bodies with Minor Atmospheres: Implications for Solid Exoplanets," has been accepted for publication in the journal Astrobiology.

Staring right at you

Although astronomers have discovered nearly 2,000 exoplanets to date, we know very little about any of them. For the vast majority, we merely possess either a mass or a size measurement. Exoplanets are simply too remote and faint for our current suite of instruments to glean tangible, worldly properties like color, surface features and cloud cover.

Our most detailed exoplanetary information so far has it that a handful of these worlds harbor gases, such as water vapor and carbon dioxide, in their atmospheres. That knowledge comes from signatures imprinted by those gases onto light that has passed through the atmosphere. The measurement, though, is indirect. The light assumed to pertain to the exoplanet is separated out from the overwhelming glare of its star.

Fujii's study goes a step further in considering worlds that we will "directly image." The distinction: The light from a directly imaged world is just from the world itself, not inferred from within a star's comparatively blinding glare. This happens to be how we study planets in the Solar System: We look right at them rather than teasing their presence out from a blaze of light.

Less than two dozen exoplanets have been directly imaged to date. The potential advantage of this technique is to be able to distinguish features on small, rocky exoplanets, the best places we think for life to arise.

Today's top-notch telescopes, like the Hubble and Spitzer Space Telescopes, will not be up to this task, however. Instead, we must wait fornext-generation telescopes and specialized instruments that can collect the planetary light more efficiently than today's instruments, separately from the host star. Several of these instruments in the works may utilize the James Webb Space Telescope, slated for launch in 2018, and the "thirty meter" class of telescopes on the ground.

From here to there

To lay a foundation for this future work, Fujii's study rendered Solar System worlds as far-off, dim exo-worlds. Fujii and colleagues collected existing data, as well as some fresh observations of Mercury, the Moon, Mars and the four Galilean moons of Jupiter (Io, Europa, Ganymede and Callisto).

Because these bodies are all relatively close, detailed maps have been made of their surfaces, consisting of thousands of pixels. Exoplanets, however, owing to their distance, can occupy only a single pixel — a so-called point source. To render Solar System bodies as point sources, Fujii averaged the total color, or brightness, of their numerous pixels down to a single pixel. (Ice, for instance, reflects more light than land, so it has a brighter color.)

As a world rotates, the brightness of this single pixel varies over time if the world's surface is not all the same. For example, when Earth rotates such that the vast Pacific Ocean faces toward an observer, the planet's overall brightness changes compared to when, say, the giant landmass of Asia swings into view.

"Due to the spin rotation, we see different slices of the surface at different times," said Fujii. "So if the brightness varies as the planet rotates, it indicates non-uniform surface material." [10 Planets That Could Host Alien Life]

Telltale light changes

The various worlds considered in the study did demonstrate average color variations over time that could be explicitly tied to factors affecting their surface compositions.

For a waterless body like the Moon, regions with potentially large contrasts to elsewhere on the lunar surface are "maria," the dark lava fields that form the pareidolic "Man in the Moon" patterns. And sure enough, the Moon stood out as a Solar System object with discernibly dissimilar light-reflecting regions.

Mercury, though it has a fairly uniformly gray color, has smooth plains covering 40 percent of its otherwise heavily cratered surface. The effect on its light reflectance patterns was similar in some ways, but not as dramatic as that of the two-tone Moon.

Io, meanwhile, jumped out thanks to its raging volcanoes, which have slathered the surface in yellows and reds, famously looking like pizza. The brightnesses of the other three Galilean moons, Europa, Ganymede and Callisto, fluctuated because of patches of darker material deposited on lighter, water ice. Ganymede's light patterns also hinted at its rumpled surface, with grooves and ridges owing to past internal heating events.

Mars, interestingly, had a lot of light variability at longer wavelengths, because fine-grained particles on the Red Planet's surface scatter these forms of light. The iron oxides, or rust, that covers a significant portion of Mars, however, are efficient at absorbing shorter wavelength light. So the notable presences and absences of certain wavelength of light told a convincing tale of what large expanses of the Mars' surface are like.

Overall, over the course of a single rotation of a planet or moon, these geological characteristics caused changes in brightness ranging from five percent to a quote noticeable 50 percent.

"Other Solar System bodies are also distinct, exhibiting various interesting surface features, some of which affect their characteristic surface colors, highlighting the amazing diversity that awaits future reconnaissance, and thus the need for continued study," said Fujii. 

Getting the basics down

The results point to how we might, with direct imaging, begin to pick out exoplanets with distinct, yet familiar geologic histories and perhaps even habitable conditions.

One major aspect that the study sidesteps is the lack of atmospheres in the chosen worlds. Intervening gases, and especially clouds, can make surface characterization difficult or impossible using direct imaging. For example, the thick, cloudy atmospheres of Venus or Saturn's moon, Titan, completely hide their faces.

But in the case of Earth, although clouded here and there, the primary surface entities of continents, oceans and ice caps, can clearly be identified even at tremendous distance, the evidence suggests.

Although indirect atmospheric characterization of habitable exo-worlds will surely precede direct surface imaging, both of these techniques will need to be brought to bear to figure out if, and what sort of, alien life has developed.

"We think this kind of survey is useful," said Fujii, "because in terms of astrobiology, we will be interested in the details of the planetary surfaces after we know the atmospheric profiles."

Along with setting aside atmospheres for now, another caveat of Fujii's study is that the first solid, potentially life-friendly exo-worlds we will likely directly image will be significantly heftier than Earth. These "super-Earths" are on the order of up to twice Earth's width and several times its mass. Per their bigness, super-Earths will be easier to find and examine.

"We wish we had super-Earth counterparts in the Solar System, because then we would definitely study their properties first," said Fujii.

Even so, building upon Fujii's results, astronomers should be well-placed to get a bead on super-Earth surfaces — at least compared to familiar Solar System objects.

"Now that we have a handful of planets and satellites in the Solar System whose properties we know in some detail," said Fujii, "we want to make the most of that knowledge, which we consider as necessary target practice."

Sweet! Deep-Space Sugars May Reveal Clues About Origins of Life...

Sugars may form in the types of ice found in deep space — a finding that could help to explain how comets and meteorites could have seeded the primordial Earth with key ingredients for life, researchers say.

In the dense molecular clouds from which stars and planetary systems are born, ices are, by far, the most abundant solids. Prior research had found that cosmic rays and ultraviolet radiation can help convert the chemicals that make up the bulk of these interstellar ices into complex organic matter, such as the precursors of proteins and fats.

"Ices are abundant in the interstellar medium, and it is unavoidable that some of them will receive energy from ultraviolet photons or cosmic rays, leading to molecular complexification," study co-author Louis Le Sergeant d'Hendecourt, an astrophysicist at the Space Astrophysics Institute in Orsay, France, told Space.com.

Now, scientists have detected sugars in experiments that mimic the way interstellar ices can evolve over time. Sugars are more than just sweet nutrients; they serve as the backbones of nucleotides, which, in turn, serve as the building blocks of the nucleic acids that make up DNA and its cousin RNA.

"DNA is the genetic source code for all known living organisms,"study co-author Uwe Meierhenrich, a chemist at the University of Nice Sophia Antipolis in France, told Space.com.

In the experiments, scientists created thin films made up of frozen water, methanol and ammonia in a vacuum chamber kept at minus 319 degrees Fahrenheit (minus 195 degrees Celsius). They irradiated these ices with ultraviolet rays to mimic how such material would evolve over time ininterstellar space. Then, they slowly warmed the samples to room temperature and analyzed them.

In a first-of-its-kind discovery, the researchers detected compounds known as aldehydes. Most sugars derive from these compounds; the simplest and best-known example of an aldehyde is formaldehyde.

Among the 10 aldehydes the scientists detected were two sugar-related compounds, glycolaldehyde and glyceraldehyde — key precursors of nucleic acids, the building blocks of genetic material.

"Glyceraldehyde is a molecule of outstanding importance," Meierhenrich said.

The researchers cautioned that their experiments did not create life, but rather only the key building blocks for life. Still, they said these findings may help reveal how ancient comets and meteorites might have seeded a lifeless Earth and other planets with the chemistry needed for life to evolve.

Future research into interstellar ices can explore the mystery of why the compounds that make up life on Earth usually come in one form but not the other, the researchers said. Many organic molecules can come in two different forms that are mirror images of each other, like left and right hands.DNA on Earth is usually "right-handed," not "left-handed," because the sugar that makes up DNA's backbone is "right-handed." In the future, the scientists would like to investigate whether sugars in interstellar ices might also be either left-handed or right-handed.

Curiosity Rover Eyes Mars Rock 'Mojave' for Drilling..

NASA's Curiosity rover may be about to collect samples from another Martian rock.

The 1-ton Curiosity rover began conducting "mini-drill" tests on a rock dubbed Mojave this week, to assess the stone's suitability for a full-up drilling and sample-collection operation. Curiosity's handlers are keen to learn more about abundant lozenge-shaped features within Mojave that appear to be mineral crystals, NASA officials said.

"The crystal shapes are apparent in the earlier images of Mojave, but we don't know what they represent," Curiosity project scientist Ashwin Vasavada, of NASA's Jet Propulsion Laboratory in Pasadena, California,said in a statement. "We're hoping that mineral identifications we get from the rover's laboratory will shed more light than we got from just the images and bulk chemistry."

The crystals may be salts left behind when a lake evaporated, or they may be the result of water moving through the rock, Vasavada added.

"In either case, a later fluid may have removed or replaced the original minerals with something else," he said.

Mojave is part of an outcrop called Pahrump Hills, which lies at the base of Mount Sharp. Mount Sharp rises 3.4 miles (5.5 kilometers) into the Red Planet's sky from the center of the huge Gale Crater.  

Curiosity has been exploring Pahrump Hills for several months now; in fact, the rover drilled into, and collected samples from, a different portion of the outcrop in September 2014. Curiosity also inspected the Mojave rock with its close-up camera and X-ray spectrometer in November.

Curiosity has conducted four sample-collecting drilling operations to date. This work — which involves the delivery of powdered rock to the rover's onboard analytical instruments — allowed mission scientists to determine that Gale Crater hosted a lake-stream system billions of years ago that could have supported microbial life.

If Curiosity does end up drilling Mojave, the operation may be complicated by a software update. The rover will likely suspend science operations for a week beginning early next week when the rover's handlers send up new flight software. It will be the fourth new version Curiosity has received since touching down on Mars on August 2012.

The software should help Curiosity drive more efficiently, among other benefits, NASA officials said.

7 Biggest Mysteries of Mars

7 Biggest Mysteries of Mars...!!

• Introduction

         Mars was known as the "fire star" to ancient Chinese astronomers, and scientists are still burning with questions regarding the Red Planet. Even after dozens of spacecraft have been sent to Mars, much remains unknown about that world. Here are some of the biggest unsolved mysteries we have about Mars.                      1. Can humans live on Mars?

To answer whether or not life did or does exist on Mars, people might actually have to go there and find out. 

NASA's plan as of 1969 was to have a human Mars mission by 1981 and a permanent Mars base in 1988. However, interplanetary human voyages pose definite scientific and technological challenges. One would have to deal with the rigors of travel — issues of food, water and oxygen, the deleterious effects of microgravity, potential hazards such as fire and radiation and the fact that any such astronauts would be millions of miles away from help and confined together for years at a time. Landing, working, living on another planet and returning from it would offer a host of challenges as well. 

Nevertheless, astronauts seem eager to find out. For example, this year six volunteers lived in a pretend spacecraft for nearly a year and a half in the so-called Mars500 project, the longest spaceflight simulation ever conducted, aimed at replicating a manned mission to Mars from beginning to end. There are even numerous volunteers for a one-way trip to the Red Planet. Tiny rock-eating microbes could mine precious extraterrestrial resources from Mars and pave the way for the first human colonists, and farmers could grow crops on its surface. The mystery as to whether or not humans will ever go to Mars may rest largely on whether or not the powers-that-be can be convinced to go there.

   

2.  Did life on Earth begin on Mars?

Meteorites discovered in Antarctica that came from Mars — blasted off the Red Planet by cosmic impacts — have structures that resemble ones made by microbes on Earth. Although much research since then suggests chemical rather than biological explanations for these structures, the debate continues. These findings do raise the tantalizing possibility that life on Earth actually originated on Mars long ago, carried here on meteorites.

3.  Is there life on Mars?

The first spacecraft to successfully land on Mars, NASA's Viking 1, began a mystery that remains tantalizingly unsolved: Is there evidence of life on Mars? Viking represented the first and so far only attempt to search for life on Mars, and its findings are hotly debated today. Viking had detected organic molecules such as methyl chloride and dichloromethane. However, these compounds were dismissed as terrestrial contamination — namely, cleaning fluids used to prepare the spacecraft when it was still on Earth. 

The surface of Mars is very hostile to life as we know it, in terms of cold, radiation, hyper-aridity and other factors. Still, there are numerous examples of life surviving in extreme environments on Earth, such as the cold, dry soils of the Antarctic Dry Valleys and the hyper-arid Atacama Desert in Chile. 

There is life virtually wherever there is liquid water on Earth, and the possibility that there were once oceans on Mars leads many to wonder if life ever evolved on Mars and, if so, whether it might be extant. Answering these questions might help shed light on how common life may or may not be in the rest of the universe.

4. Were there oceans on Mars?

Numerous missions to Mars have revealed a host of features on the Red Planet that suggest it was once warm enough for liquid water to run across its surface. These features include what appear to be vast oceans, valley networks, river deltas and minerals that required water to form. 

However, current models of early Mars' climate cannot explain how such warm temperatures could have existed, as the sun was much weaker back then, leading some to ask whether these features might have been created by winds or other mechanisms. Still, there is evidence suggesting that ancient Mars was warm enough to support liquid water in at least one site on its surface. Other findings hint that ancient Mars was once cold and wet, not cold and dry nor warm and wet, as is often argued.

5. Does liquid water run on the surface of Mars now?

Although large amounts of evidence suggest that liquid water once ran on the surface of Mars, it remains an open question as to whether or not it occasionally flows on the face of the Red Planet now. The planet's atmospheric pressure is too low, at about 1/100th of Earth's, for liquid water to last on the surface. However, dark, narrow lines seen on Martian slopes hint that saltwater could be running down them every spring.

6.  What is the source of methane on Mars?

Methane — the simplest organic molecule — was first discovered in the Martian atmosphere by the European Space Agency's Mars Express spacecraft in 2003. On Earth, much of the atmospheric methane is produced by life, such as cattle digesting food. Methane is suspected to be stable in the Martian atmosphere for only about 300 years, so whatever is generating this gas did so recently. 

Still, there are ways to produce methane without life, such as volcanic activity. ESA's ExoMars spacecraft planned for launch in 2016 will study the chemical composition of Mars' atmosphere to learn more about this methane.

7.   Why does Mars have two faces?

Scientists have been puzzling over the differences between the two sides of Mars for decades. The northern hemisphere of the planet is smooth and low — it is among the flattest, smoothest places in the solar system, potentially created by water that once flowed across the Martian surface.

Meanwhile, the southern half of the Martian surface is rough and heavily cratered, and about 2.5 miles to 5 miles (4 km to 8 km) higher in elevation than the northern basin. Recent evidence suggests the vast disparity seen between the northern and southern halves of the planet was caused by a giant space rock smacking into Mars long ago.

Fresh Crater on Mars Spied by NASA Spacecraft (Photo)

A NASA Mars probe has photographed an impact crater that was blasted out of the Red Planet in just the last few years.

The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter (MRO) captured the crater, which lies in the Red Planet's equatorial Elysium Planitia region, on Dec. 2, 2014. Scientists say the impact that gouged out the hole must have occurred between February 2012 and June 2014, based on previous images of the area.

The crater is about 40 feet (12 meters) wide, said HiRISE team member Ingrid Daubar of NASA's Jet Propulsion Laboratory in Pasadena, California

"We've been finding new craters like this for a few years now, and from studying their frequency, we've come up with a cratering rate for Mars based on them," Daubar told Space.com via email.

"For craters this size (12 m diameter), we expect about 30 of these are forming over all of Mars each year," she added. "We only find a few of them, though, because we have to be looking in the right area. They're not as easy to find over non-dusty areas where they don't form these huge dark blast zones around the impact site."

The new photo is the first one HiRISE — short for High Resolution Imaging Science Experiment — has taken of the crater. The feature was actually discovered by MRO's Mars Context Camera, NASA officials said.

The objects that create Martian craters such as this one strike the surface at very high speeds — an average of 22,000 mph (35,400 km/h) — and are almost always completely destroyed in the process, Daubar said.

Indeed, there is no sign of the impactor in the new HiRISE photo. The silvery crescent toward the right side of the crater is just the illuminated interior wall of the crater, Daubar said. (In the image, sunlight is coming from the lower left.)

The $720 million MRO mission launched in August 2005 and arrived in orbit around Mars in March 2006. The spacecraft has been studying the Red Planet ever since with six scientific instruments. MRO also serves as a vital communications link between Earth and NASA's active Mars surface craft, the Opportunity and Curiosity rovers.

Search for Mars Life Starts on Earth...!!

Frigid lakes bombarded by UV radiation and boiling, acidic springs are some of the otherworldly Earth environments where scientists plan to hunt for clues to life on Mars.

Funded by a new, five-year NASA grant, the researchers will tour the three ages of Mars on Earth — when Mars was cold, wet and habitable; the transition period when water disappeared; and the modern, dry period. The Mars-like environments include hot springs in California and Yellowstone National Park, permafrost on cold Arctic islands, some of Earth's oldest rocks in Australia, and volcanic lakes and soils in Chile.

"We chose these environments because we want to understand the signature of life on Mars at different times," said Nathalie Cabrol, the project leader and a senior research scientist at the SETI Institute in Mountain View, California.

The SETI-led team will scope out "biosignatures," or evidence of life, with instruments similar to those NASA plans to install on the next Mars rover, expected to launch in 2020. The car-size robot is designed to seek out ancient life.

On Mars, the clues could be concealed in rocks more than 3.5 billion years old. If the planet's ancient environment was akin to that of early Earth, then the rover might discover fossils of microbial mats similar to stromatolites, which are some of Earth's oldest fossils. Or primitive microbes could have left behind chemical calling cards, such as the altered minerals created by rock-eating bacteria known as chemolithotrophs. The rover may also find subtle shifts in carbon, hydrogen and nitrogen isotopes, trapped and preserved in rock layers, which can signal the presence of life. (An isotope is an atom of an element with a different number of neutrons.)

Cabrol and her team will practice searching for promising rocks from the air, by scanning sites with a quadcopter or octocopter, she said. They'll also analyze samples in the field with portable instruments, and in a laboratory for more-precise measurements.

"Our goal is not to prove more efficient at finding biosignatures," Cabrol told Live Science. "We want to get metrics and data that will lead us to detection."

By honing their skilles in Earth's extreme environments, the scientists will learn where and how to look for life for when the rover arrives at Mars. The research may also help narrow down the list of best landing sites for the rover.

"We're not saying we're going to detect life, but we're increasing the chances we're going to the right outcrop," Cabrol told Live Science.

The $8 million grant is one of five awarded to seven research groups across the United States to study the origin of life. The teams will be affiliated with NASA's Astrobiology Institute at Ames Research Center in Moffett Field, California.

Stellar Spin Reveals Stars' Birthdays

Using NASA's planet-hunting Kepler spacecraft, scientists have refined their ability to nail down the ages of individual stars by measuring the objects' mass and how quickly they rotate.

"Our goal is to construct a clock that can measure accurate and precise ages of stars from their spins," lead author Soren Meibom, of the Harvard-Smithsonian Center for Astrophysics (CfA), said in a statement. The new findings were presented at a press conference during the 225th winter meeting of the American Astronomical Society(AAS) last week in Seattle.

"We've taken another significant step forward in building that clock," Meibom added.

Age ain't nothing but a number

Like sunspots on the sun, distant stars host dark spots on their surface known as starspots. These markings travel across the stars as they rotate, causing a slight dimming in the light the stars produce.Determining the age of a star isn't as simple as counting the candles on its birthday cake. But understanding stellar age is crucial in determining how astronomical phenomena involving stars and their companionsprogress over time.One way to determine the age of a star is by calculating how quickly it spins. Over time, the rotation of a star slows steadily. How swiftly it turns is also related to its mass; larger, heavier stars spin faster than smaller, lighter ones. Meibom and his colleagues discovered close relationships among mass, spin and age. By measuring the first two attributes, scientists can determine the third, study team members said.

"We have found that the relationship between mass, rotation rate and age is now defined well enough by observations that we can obtain the ages of individual stars to within 10 percent," co-author Sydney Barnes, of the Leibniz Institute for Astrophysics in Germany, said in the same statement.

In 2003, Barnes proposed the method of correlating the three characteristics, calling it "gyrochronology" from the Greek words "gyros" (rotation), "chronos" (time or age) and "logos" (study).

In addition to helping scientists understand astronomical processes, learning the age of a star can also aid in the search for life beyond the solar system, researchers said. It took several billion years for complex life to develop on Earth. An accurate stellar clock allows scientists to identify planet-hosting stars as old as, or older than, the sun.

The spotted stars

While sunspots are relatively easy to measure from Earth, stars remain bright points of light, so their starspots aren't directly visible. Instead, astronomers watch for the star to dim slightly as a spot crosses its surface, then brighten again as the sunspot rotates off the visible surface. The changes in brightness can be a challenge to detect. On average, a star dims by less than 1 percent, and starspots can take days to move across the surface, researchers said.

But Kepler was up to the challenge. The spacecraft is designed to detect tiny brightness dips, which can also be caused by planets crossing theface of their host stars. Kepler's observations of stellar brightness allowed the team to make precise measurements to refine their calculations.

To measure the links among the three characteristics, the team pointed Keplerat stars with previously calculated ages to determine the objects' spin rates. In previous work, the scientists had studied a cluster of billion-year-old stars; the new study targeted NGC 6819, a 2.5-billion-year-old cluster, significantly improving the stellar age range of stars in the study.

"Older stars have fewer and smaller spots, making their periods harder to detect," Meibom said.

The team targeted 30 stars that harbored from 80 to 140 percent of the mass of the sun. Their spins varied from 4 to 23 days, compared to the 26-day rotation of the sun.

The eight stars from NGC 6819 that bear the strongest resemblance to the sun have an average spin of 18.2 days, suggesting that Earth's star had a similar rotation 2 billion years ago, when it was 2.5 billion years old.

The team then determined which of several existing computer models that calculated the spin of stars based on their masses and ages best matched the researchers' observations.

"Now we can derive precise ages for large numbers of cool field stars in our galaxy by measuring their spin periods," Meibom said. "This is an important new tool for astronomers studying the evolution of stars and their companions, and one that can help identify planets old enough for complex life to have evolved."

In addition to being presented at AAS, the new study was published online in the journal Nature.